Hotbed for rails



Patenred Apr.^26, 193s I .UNITED s'rATEs PATENT OFFICE 24154590 Borneo Fort nAILs Application October 10, 1931, Serial No. 568,140 In Great Britain June 26, 1931 9 Claims.

This invention relates to a novel apparatus for controlling the Cooling of rails or the like as they leave the rolls of a rolling mill.

A rolling mill for rolling rails is ordinarily associated with a lhot bank on which the rails are placed when they have left the rolls, either direCtly or after some preliminary Cooling operation, and on which they remain until they have cooled more or less completely.

In the art of rolling railway or tramway rails precautions should be taken to control the cooling of the rail when it has left the mill. ticul'ar, as has been explained in the specification. of our application Ser. No. 543,4'78, filed Junev 10,

' 1931, care should be taken that when the temperature of the rail, which has left the mill at a temperature above the well-known Critical range, has fallen to a point not consequentiallylower than 500 C., the further cooling should occur under such conditions that the interior and exterior portions of the mass of the rail, especially the big mass of the rail head, should have substantially uniform temperature and that this unlformity should be maintain'ed as far as possible while the Cooling proceeds to about 350 C., whereafter it is of nolparticular importance under -what conditions the further Cooling to atmospheric temperature takes place. V

One of the objects of the present invention is to provide an apparatus in the form of a Chamber or oven adapted to retard the rate of Cooling of rails emerging from a rolling mill and control the nature of such Cooling within. a certain range or-ranges of temperature. More particularly this object is attained by a Chamber having two functions one of which is to equalize as far as possible the temperature throughout the hot rolled products as they approach a predetermined temperature whilst the other is to then control the cooling of the same through a predetermined'range 'so that the Cooling is uniform, that is to say, is such that no substantial temperature difierentials in the body of each rail develop while it is cooling through such range.

A further object of the invention is to provide a Chamber or oven as' aforesaid comprising two or more portions or Compartments the first of Which brings about the equalization of temperature referred to, whilst one or more remaining Compartments produce a retarded cooling such that the rails undergo a uniform bodily Cooling.

The oven or Chamber according to the present invention is also preferably transportable so that it can be shifte'd to take up any desiredposition along .the hot bank or alongside the same.

In pari In order to permit of travel of the rails in succession through the Chamber without unduly disturbing the temperature conditions therein, the entrance and exit spaces may be normally closed by suitable means such as hinged flaps ca- 5 pable of being deflected by the articles as they enter and leave the Chamber.

Referring to the drawings:--

Figure 1 is aplan view of a hot bank, a series of live rollers for delivery of rails from a rolling mill 10 to the bank, and an oven or Chamber extending over a portion of the hot bank.

Figure 2 is a sectional side elevation and Figure 3 is a sectional end elevationa of the plant shown in plan in Figure l.

Figure 4 is an enlarged sectional end elevation of a slightly modified form of Athe oven or chamber. i

Figure '5 is a fragmentary cross section of a further modified form of Chamber. 20

Referring first more particularly to Figures l,

2, and 3, it is seen that the rails delivered still hot from the rolling mill travel endwise along the live rollers i until they arrive next to the hot bank 2 and are th'en'passed manually or mechanically 25 to and along the hot bank, and eventually enter the oven. 3. It is to be observed that the rails travelalong the hot bank side by side so that when they enter the oven each rail undergoes sub- .stantially the same thermal treatment at all 30 points along it.

The oven 3 has two portions or compartments 04 and 5 (see Fig. 3) each of Which comprises a roof v Which extends across the hot bank in a single span by being suitablysuspended by girder work 6. The roof 'i of the first compartment 4 is arched and composed of or lined with refractory material that is a, poor conductor of heat such as fireclay, silica bricks orl asbestos, Whilst the roof t of the second Compartment 5 may be of metal 40 without any lining, or if lineci may have a lining less massive than that used for the first compartment. As shown the roof 8 is a lean-to in relation to the roof 1, this being a simple and convenient construction.

Means, such as burners Q extending downwards through the roof 'I from a gas supply main Hi are provided to enable the necessary temperature to be attained and maintained within the compartment t.

It will beobvious that the temperature of compartment t is higher than that of compartment 5. The two compartments are soconstructed, as just pointed out, that the loss of heat from' coml partment 4 will be at a considerably slower rate 55 till than the loss of heat from compartment 5. Moreover, compartment 4 is provided with means for adding heat, namely the burners, while" compartment 5 does not have such means.

It is desirable that the Chamber or oven should effectively enclose or cover a section of the hot bank, (or the floor of the site selected if the Chamber is not placed on the hot bank) in such a manner that the sides as well as the ends of the structure are brought down to or near to the level of the hot bank or floor. For example, sufiicient clearance may be made for the entrance and exit of the rails beneath the sides of the chamber, or as shown in the drawings the clearances may be provided with depending fiaps ll and I 2 which are deflected by each rail as it enters and leaves the Chamber, but effectively close the Chamber when the rails are inside.

If desired, there may be a partition between the compartments, which partition may depend from the roof with the necessary clearance beneath it, or may be constituted by a flap of the aforesaid kind as shown at l3.

It is preferable that the floor space beneath the roof, or at all events the floor space of the first compartment, should be paved with a suitable material, such as refractory brick I4, so as to prevent loss of heat and the introduction of draughts.

It is evident that the oven 3 provides a relatively dead air space for the rails. The regular hot bed or hot bank without the oven or cover facilitates a circulation of the air about the cooling rails, the hot air rising and the cold air coming up from beneath the rails. The oven 3 greatly Checks this air circulation, the space enclosed by the oven thus being a relatively dead air space. The oven or cover performs this function especially well when the floor space is paved, as indicated at I 4.

The oven or Chamber shown in Figure 4 is substantially the same as that shown in Figur-es l, 2, and 3, but the heating means are duplicated as shown.

The chamber or oven described above may be stationary or adapted to travel so as to be placed over any part of the hot bank, or over any part of its site which may be adjacent to the hot bank.

If adapted to travel the Chamber or oven is mounted upon flanged wheels |5 placed at its extreme ends, and running upon rails IB beneath. The oven may be moved either manually or by power.

The rails, or other rolled products, are conveyed into and through the Chamber or oven by means of apparatus such as is generally used for Conveying rails alongr a hot bank. The temperature at which the rails enter and leave the Chamber or oven is determined b-y pyrometers, or other suitable means, and the length of time the material remains in the Chamber is governed thereby.

When the rails are moved from the live rollers l along the hot bank 2, they pass beneath the flap Ii and enter the compartment 4, their temperature at the time of entry preferably being not lower than about 500 C. at their external surface. Here they remain, either at rest or in slow motion, until sufiicient time has elapsed for the temperature of the interior and exterior of the mass of the rail, particularly that of the rail head, to become approximately uniform and during which time any Cooling is very much retarded. The rails are then moved into the second compartment 5 where they remain either at rest or in slow motion for a lapse of time suflicient to ensure that their temperature has fallen slowly to about 350 C.

It is to be understood that the invention is independent of any heat treatment which the rails or other rolled products may have received prior to their entry into the chamber or oven and that it is also independent of any further Cooling treatment to which they may afterwards be sublected.

Although the invention has been described with reference to certain structural embodiments it is to be understood that it is not to be regarded as limited thereto and that various Constructional modifications may be resorted to within the scope of the appended claims. For example, the oven or Chamber may extend over a floor space adjacent the hot bank instead of over an actual portion of the hot bank so that the rails will temporarly leave the hot bank for treatment in the oven' or Chamber and then return to it.

Having thus described our invention what we claim as new and desire to secure by Letters Patent is:--

1. In a rail treatment apparatus, a hot bed and a rail protective cover extending across the hot bed and adapted to cover but a portion thereof disposed in proximity to the top of the hot bed to provide a relatively dead air space for the' rails covered thereby.

2. In a rail treatment apparatus, a hot bed and an oven of hood like formation adapted to extend across the hot bed and to cover but a portion thereof, and a heat retaining floor for that portion of the hot bed beneath said oven.

3. In a rail treatment apparatus, a hot bed, an oven of hood like formation adapted to extend across the hot bed of width suicient to cover a plurality of rails on but a portion of the hot bed, and means for varying the temperature in the oven.

4. In a rail treatment apparatus, a hot bed, an oven of hood like formation adapted to span the hot bed of width sufiicient to cover a plurality of rails on but a portion of the hot bed, and means for effecting relative transverse movement of the rails and oven.

5. In a rail treatment apparatus, a hot bed, an oven of hood like formation adapted to span the hot bed of width sufficient to cover a plurality of rails on but a portion of the hot bed, and means for effecting movement of the oven transversely of the rails on the hot bed.

6. In a rail treatment apparatus, a hot bed, an

oven of hood like formation adapted to extend across the hot bed substantially parallel with the rails thereon and being of a width to cover a plurality of rails on but a portion of the hot bed, said oven having a plurality of Compartments adapted to successively cover the rails upon relative transverse movement of the rails and oven.

'7. In a rail treatment apparatus, a hot bed, an oven of hood like formation adapted to extend across the hot bed substantially parallel with the rails thereon and being of a width to Cover. a plurality of rails on but a portion of the hot bed, said oven having a plurality of compartments adapted to successively cover the rails upon relative transverse movement of the rails and oven, and means for obtaining different temperature conditions in the different compartments.

multi-compartment Chamber having different'V capacities for retaining heat, means for suspending the roofs of said compartments in a single span across the hot bed to cover but a portion thereof, and means for reguiating the thermal conditions within one of said compartments.

9. In a rail treatment apparatus, a hot bed, a Chamber for retarding the rate and controlling the cooling of the hot rails' covering but a portion of the hot bed, said portion of the hot bed being paved to constitute av heat-retaining floor for said chamber; .end walls, a single span roof extending over said fioor, side walls extending from said roof to Within a distance from said floor to permit hot rolled products from the mill to pass beneath them, fiaps defiectable by said products as they pass under said side walls into and out of said chamber, and heating means for applying controlled heat to said Chamber. 

